Field of the Invention
This invention relates to optical display technologies, and in particular, it relates to a light source system and a projection system.
Description of Related Art
With the development of projection display technologies, the technology has developed from the original single-chip DMD (Digital Micromirror Device) projection systems to three-chip DMD projection systems.
In conventional single-chip DMD display technology, the light source is a white light source. The white light is filtered to sequentially generate red, green and blue primary color lights; the red, green and blue lights are sequentially inputted to the DMD, and processed by the DMD to be output. Although such single-chip DMD projection systems have a simple structure, its light utilization efficiency is very low, as most light is loss in the filtering step. This results in low brightness of the projection system. Moreover, by using a single DMD to sequentially process the red, green and blue lights, the color switching speed is limited, causing a “rainbow” effect. To solve the above problems, three-chip DMD projection technology is developed. A three-chip DMD projection system uses a white light source; the white light is split by a prism into red, green and blue primary color lights which are inputted to three DMDs, which separately process the received lights. Compared to single-chip DMD projection systems, three-chip DMD projection systems have higher light utilization efficiency. But such a system has a relatively complex structure and are more difficult to install, and are relatively costly.
How to balance the need for higher light utilization efficiency and overall cost is a challenge in this area of technology. In response, two-chip DMD projection systems are developed. For example, U.S. Pat. No. 5,612,753 and US Pat. Appl. Pub. No. 2012/0257124 disclose two-chip DMDs. Although such systems have a relatively simple structure as compared to three-chip DMD, their brightness is not ideal, and they still cannot fully solve the undesirable “rainbow” problem. Therefore, there is a need for a new of light source system, which can deliver high brightness and solve the problem of the “rainbow” effect at the same time.